Prior art switched diversity receivers are well known as shown, for example, in U.S. Pat. No. 2,729,741, U.S. Pat. No. 2,872,568 and in the following articles; Takeda et al, "FM Multipath Distortion in Automobile Receivers Has Been Significantly Reduced by a New Antenna System", IEEE Transactions on Consumer Electronics, pp 263-269 Vol. CE-26, August 1980; Finger et al, "FM Receivers in Automobiles: A Case For Diversity Reception" IEEE Trans. on Consumer Electronics, Vol. CE-27, pp. 51-61, February 1981; and Parsons et al, "Diversity Techniques for Mobile Radio Reception" IEEE Trans. on Vehicular Technology, Vol. VT-25 No. 3, pp. 75-85 August, 1976. These diversity receiving systems employ two antennas which are spaced apart and/or which have different polarizations. One of the two antennas is connected to the FM receiver by means of a relay switch, which switch is controlled by a circuit which is responsive to a measure of the detected, or demodulated, receiver signal. Many prior art control circuits are insensitive to rapid changes in the received signal and, therefore, often fail to connect the antenna having the best signal to the receiver.